This invention is concerned with a mesh or fabric which may be either knit or woven. The fabric is made from either a tissue absorbable material such as polyglycolic acid (herein PGA) fibers, or from a partially tissue absorbable material such as mixtures of PGA fibers and fibers of a nonabsorbable polyester or polyamide, or fibers of another medically acceptable nonabsorbable material. It is to be understood that the term polyglycolic acid is generic to both the homopolymer and to copolymers containing a glycolic acid ester linkage.
The mesh or fabric has varying amounts of stretch, including zero stretch in the warp or in the weft (filling) direction.
The mesh or fabric may be useful in a wide variety of internal surgical procedures, e.g. as a tamponading device for pressure encapsulation and repair of traumatically damaged organs such as the spleen, liver or kidney. The mesh or fabric may also be useful as a zero stretch or low stretch material e.g. in the repair of an abdominal wall defect, hernia, urinary tract, etc. Further, the mesh or fabric may be useful in areas of the cardiovascular system and in the brain. Still further, the mesh or fabric may be useful in oral surgery, for example to repair defects and to encourage tissue ingrowth.
Although the dimensions and weight of the mesh are only limited by the practical size for its intended use, dimensions of from 4.times.4 inches to 10.times.13 inches and weights of 0.75 to 6.5 ounces per square yard can be normally used. Openings in the mesh can range normally from zero to 1/4 inch. The mesh can also be manufactured as a tubular prosthesis.
A drawing which describes the shape and/or geometrical configuration of the mesh or fabric is not necessary for an understanding of this invention. That is, any person skilled in the mesh or fabric art will know how to manufacture and how to use the invention by reading this specification, generally and the examples, specifically.
In order to further stabilize the fabric, that is to eliminate horizontal or vertical edge curling and regulate stretch, the fabric may be heat set by holding both length and width to a specified dimension within a pin or clip frame while exposing the material to temperatures of 90.degree. to 175.degree. C. for periods of 30 seconds to 15 minutes, preferably in a vacuum. The fabric may also be heat set by holding both the length and width to a specified dimension on a heated cylinder while exposing the material to temperatures of 90.degree. to 175.degree. C. for periods of up to 4 hours in a vacuum.
A knitted surgical mesh has been invented. The mesh comprises a plurality of filaments. Each filament is manufactured from a polymer having a glycolic acid ester linkage. The filaments are bundled or twisted into a yarn, and the yarn is knitted into a mesh.
In one embodiment, the polymer is a homopolymer. In another embodiment, the polymer is a copolymer. In a more specific embodiment, the copolymer is manufactured from glycolide and from trimethylene carbonate.
In yet another embodiment, the yarn manufactured from the homopolymer is greater than about 60 denier and contains up to 4 plys. Each ply has greater than about 25 filaments. In a more specific embodiment, the yarn is up to about 150 denier, and the total number of filaments per yarn is up to about 75.
In still another embodiment, the yarn manufactured from the glycolide and trimethylene carbonate copolymer is about 65 to 85 denier. The yarn contains about 5 to 25 filaments.
In still another embodiment, the knitted mesh is manufactured on a 14 gauge tricot knitting machine wherein the stitch design is
______________________________________ Front Bar (2/0 2/4) .times. 2 (4/6 4/2) .times. 2 and Back Bar (4/6 4/2) .times. 2 (2/0 2/4) .times. 2. ______________________________________
In yet another embodiment, the weight of the mesh is about 4 to 10 oz./sq. yd. In a further embodiment, the quality of the mesh is about 10 to 20 inches per 480 courses.
A knitted surgical fabric has also been invented. The fabric comprises a plurality of filaments. Each filament is manufactured from a polymer having a glycolic acid ester linkage. The filaments are bundled or twisted into a yarn, and the yarn is knitted into a fabric.
In one embodiment, the polymer is a homopolymer. In another embodiment, the polymer is a copolymer. In a more specific embodiment, the copolymer is manufactured from glycolide and from trimethylene carbonate.
In yet another embodiment, the yarn manufactured from the polymer is up to about 150 denier and contains up to about 75 filaments. In a more specific embodiment, the yarn is about 100 to 135 denier and contains about 40 to 75 filaments.
In still another embodiment, the knitted fabric is manufactured on a 48 gauge Raschel knitting machine wherein the stitch design is
Front Bar: 1/0 0/1
and Back Bar: 1/0 4/5.
In yet another embodiment, the weight of the fabric is about 4 to 10 oz./sq. yd. In a further embodiment, the quality of the fabric is about 10 to 20 inches per 480 courses.
A woven surgical fabric has been invented. The woven fabric comprises a plurality of filaments. Each filament is manufactured from a polymer having a glycolic acid ester linkage. The filaments are twisted into a yarn, and the yarn is woven into a fabric.
In one embodiment, the polymer is a homopolymer. In another embodiment, the polymer is a copolymer. In a more specific embodiment, the copolymer is manufactured from glycolide and from trimethylene carbonate.
In yet another embodiment, the yarn manufactured from the polymer is less than about 300 denier, and the yarn contains at least about 3 plys. In a more specific embodiment, the yarn is about 40 to 250 denier and contains about 5 plys. The total number of filaments per yarn is about 50 to 150.
In a still further embodiment, the warp yarn of the woven fabric has about 2 to 7 twists per inch and the filling yarn has about 1/2 to 5 twists per inch. In a yet further embodiment, the weight of the fabric is about 1 to 6 oz./sq. yd.